State Route 99 over Hamilton Slough
GoodButte County, California · 03-BUT-099-8.21 · Structure no. 12 0003
- Built
- 1950
- 75 years old
- Condition
- Good
- inspected April 2023
- Type
- Slab
- Concrete Continuous
- Length
- 80 ft
- 4 main spans
- Daily traffic
- 11,050
- 2020 count
- Owner
- State
- State Highway Agency
About this bridge
State Route 99 over Hamilton Slough is a concrete continuous slab carrying State Route 99 over Hamilton Slough in Butte County, California. It was built in 1950, so it is 75 years old, older than the California average of 54.8 years.
The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
It carries about 11,050 vehicles a day, roughly 10% of them trucks, projected to reach 21,231 by 2041. The structure is 80 ft (24.4 m) long and 42 ft wide. If it were closed, the detour would be 5 mi (8 km).
Location
Open in Google MapsCondition and inspection
All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 7 Good | Some minor problems. |
| Superstructure | 7 Good | Some minor problems. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was State Route 99 over Hamilton Slough built?
It was built in 1950, making it 75 years old in 2025.
What condition is State Route 99 over Hamilton Slough in?
The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in April 2023.
How much traffic does State Route 99 over Hamilton Slough carry?
About 11,050 vehicles per day (2020 count), of which roughly 10% are trucks.
How long is State Route 99 over Hamilton Slough?
The structure is 80 ft (24.4 m) long with a longest span of 22 ft (6.7 m) and a deck 42 ft wide.
Who owns State Route 99 over Hamilton Slough?
It is owned by the State Highway Agency.